Reworking of the Tarim Craton by underplating of mantle plume-derived magmas: Evidence from Neoproterozoic granitoids in the Kuluketage area, NW China
MetadataShow full item record
Most Neoproterozoic granitoids in the Kuluketage area, northern Tarim Craton are characterized bystrongly depleted HREE abundances and high Sr/Y and (La/Yb)N ratios, showing typical geochemical features of adakitic rocks. Zircon U–Pb dating of three adakitic plutons yielded Neoproterozoic ages (754±4, 790±3 and 798±3 Ma). The adakitic granitoids exhibit low MgO and TiO2 contents. Their low Cr, Co and Ni abundances, low eHf(t) values (-21 to -11) and high FeOT/MgO ratios (mostly 2.2–2.9) preclude the possibility of being derived from partial melts of delaminated lower crust. The relatively low eHf(t) values and old Hf two-stage model ages (T2 DM = 2.42–3.02 Ga) of the adakitic granitoids are similar to those of the basement rocks in the northern Tarim Craton, suggesting that the adakitic rocks were generated by partial melting of basement rocks in a thickened lower crust. Apart from the adakitic granitoids, Neoproterozoic normal I-type granitoids with low Sr/Y and (La/Yb)N ratios are also exposed in this area, and their geochemistry indicates a crustal origin at a shallower depth. Zircon U–Pb dating of the I-type granitoids also yielded a Neoproterozoic age of 785±8 Ma. The petrogenesis of the Neoproterozoic adakitic granitoids suggests that Neoproterozoic crustal thickness in the northern Tarim Craton must have been over 50 km. In combination with the occurrence of coeval mantle-derived dykes and bimodal volcanic rocks, a partial melting scheme triggered by underplating of mantle plume-derived magmas is proposed to interpret the formation of the Neoproterozoic adakitic and I-type granitoids. This model provides an alternative interpretation for the Neoproterozoic craton reworking happened in the Rodinia supercontinent.
Showing items related by title, author, creator and subject.
Reworking of the Tarim Craton by underplating of mantle plume-derived magmas: Evidence from Neoproterozoic granitoids in the Kuluketage area, NW ChinaLong, X.; Yuan, C.; Sun, M.; Kröner, A.; Zhao, G.; Wilde, Simon; Hu, A. (2011)Most Neoproterozoic granitoids in the Kuluketage area, northern Tarim Craton are characterized by strongly depleted HREE abundances and high Sr/Y and (La/Yb)N ratios, showing typical geochemical features of adakitic ...
Synchronous crustal growth and reworking recorded in late Paleoproterozoic granitoids in the northern Tarim craton: In situ zircon U-Pb-Hf-O isotopic and geochemical constraints and tectonic implicationsGe, R.; Zhu, W.; Wilde, Simon; He, J.; Cui, X. (2015)Identifying the relative contribution of various crustal and mantle materials in the source of granitoids is crucial for the study of granite petrogenesis and crustal growth. Extensive and diverse late Paleoproterozoic ...
Early Pan-African magmatism in the Tarim Craton: Insights from zircon U-Pb-Lu-Hf isotope and geochemistry of granitoids in the Korla area, NW ChinaGe, Rongfeng; Zhu, W.; Zheng, B.; Wu, H.; He, J.; Zhu, X. (2012)Extensive Neoproterozoic magmatism occurred in the Tarim Craton, providing a key to understanding the role of Tarim in the Rodinia and Gondwana supercontinents. We present LA-ICP-MS zircon U-Pb ages, Lu-Hf isotopic data ...